给表起别名的方式读取关联查询结果

 val url = "jdbc:postgresql://192.168.1.1:5432/test"
 val prop = new Properties()
 prop.setProperty("user", "test")
 prop.setProperty("password", "test")
 prop.setProperty("driver", "org.postgresql.Driver")
 val sql ="(select * from  p_run run Left Join  wq_vehicle  vehicle on run.vid=vehicle.vid Left Join wq_tbobd obd on run.vid = obd.vid and  run.utc=obd.utc where run.utc >= '2018-11-16 00:00:00' and run.utc < '2018-11-17 00:00:00' ) a ";
val dfData: DataFrame = sqlContext.read.jdbc(url,sql,prop)